Setting: I am writing a piece set in the "dark ages" around the time of Geoffrey of Monmouth and Arthurian legends. In the fandom canon knowledge and treatment of diseases and injuries is more advanced than it actually was at the time. For example there is knowledge of the scientific method and the use of a variety of herbs (some anachronistic) made into salves, potions etc.
My character is in his early-20s, in peak physical condition, but is recovering from a near-fatal bite (to the shoulder) from a mythical beast. He suffers a broken arm due to his trying to fetch some horses. My scenario is that the horse reared and he fell backwards onto one arm. In my fic this results in a compound fracture of the humerus, but I would appreciate any secondary opinion on how likely this is.
Anyway, after the break he passes out and lays there for around 3-4 hours. My question is how much blood would he lose in this period, considering that he was wearing only a thin tunic (it's summer). I know that arm breaks are unlikely to cause death but would he be susceptible to infection or blood loss in this case? He passes out in the middle of a forest and it takes a long time for anyone to find him.
After the 3-4 hours another character finally finds him. It is dark, she is alone and has nothing on her except her sword and probably a small dagger (all their equipment was carried by the horses, which escaped). He is alive and conscious (see previous question) but is obviously in great pain. From what I have read she should splint his arm however this is in an age where x-rays and ambulances don't exist. It is night-time in a forest, so what could she make a splint out of? She can tear fabric off her sleeves and I'm thinking of using wood, but that's obviously a little unhygienic.
Assuming that she is able to treat him, they then must make a 1-2-mile walk back to civilisation. Is he likely to be able to attempt such a journey? Or should she leave him and fetch some horses? I'm thinking the latter is more likely, but it is obviously dangerous to leave an injured person on their own in the dark. After they return to civilisation, how would the injury be treated? Currently I think it would just be splinted (after adjustment) and left to its own devices, but please correct me if I'm wrong. How would the break heal and would the break affect the arm's strength etc. in later life (assuming that the broken arm is not the one attached to the shoulder damaged by the bite)?
Sorry for all the questions, I have no background knowledge on any of this :x I have googled: first-aid, broken arms, treatment of fractures in medieval times. Most of the time I have gotten knowledge of first-aid in modern times and the information about medieval treatment was often not directly relevant to the treatment of fractures, or did not describe treatment in a first-aid situation.
Thank you very much for any help!